Site-specific electronic structure of Pr in Pr1+xBa2-xCu3O7-δ

Abstract

We report on resonant x-ray powder-diffraction measurements in the vicinity of the Pr L3 absorption edge of Pr1+xBa2-xCu3O7-δ. The Pr site occupation has been accurately determined: 6±2% of the Pr is on the Ba site. From an analysis of the energy dependence of selected Bragg reflections, the site-specific oxidation state of Pr has been obtained. These results are discussed in the context of models describing the suppression of superconductivity by Pr, and they indicate that Pr on the R site is responsible for Tc suppression. © 2001 The American Physical Society.